Equatorial electrojet parameters and the relevance of Electromagnetic Drifts (EMD) over Thumba

Abstract

The thermal imbalance in theE-region heights is inescapable and an undisputed fact. The equatorial electrojet parameters are being evaluated for an Indian Equatorial station of Thumba, making use of the observed electron density, electron temperature, and current density profiles for two rocket flights on 3 March, 1973 and 7 April, 1972 around local noon, corresponding to low and medium solar active conditions. The computed Joule heating due to Equatorial Electrojet Current (EEC) does not account for the observed difference between the electron and neutral gas temperatures. The discrepancy of about 6 km in the peaks of the observed and computed current density profiles may be attributed to the presence of the Electromagnetic Drifts (EMD). In order to see whether or not EMD plays an important role, the photoionization balance between production and loss rates have been computed by making use of the latest available solar flux and cross sections and chemical reaction rate constants for the appropriate solar epoch conditions including the transport term due to EMD. There is an excellent agreement between the observed and computed electron density profiles indicating its relevance.